yii-application is the name of the dir where you want to install the application. Its an advanced app. you can specify yii2-app-basic to create basic app.

3. Initialize directory structure
cd to yii-application dir and run.

php init

select 0 as dev environment. This command creates the basic structure of the directories.

4. Connect DB
Create a new database and adjust the components.db configuration in common/config/main-local.php accordingly.

5.
Apply migrations with console command yii migrate.

6.
Set document roots of your web server:
for frontend /path/to/yii-application/frontend/web/ and using the URL http://frontend/
for backend /path/to/yii-application/backend/web/ and using the URL http://backend/